[FFmpeg-user] rc buffer overflow (codecs mpeg4, flv)

Mike Scheutzow mike.scheutzow at alcatel-lucent.com
Fri Apr 13 16:50:10 CEST 2012

Andrey Utkin wrote:
> It gives 'rc buffer underflow' warnings (more times on high-motion input video).
> Visually, it manifests as remarkable picture quality degradation after
> such message is produced.
> Is this really a bug, or my misuse of parameters? If it's a bug, is it
> known, and how can i help fixing it?
> ffmpeg -i ~/big_buck_bunny_480p_surround-fix.avi -an -vcodec flv -s
> 192x144 -b:v 100000 -maxrate 100000 -minrate 100000 -bufsize 100000
> -y out.flv -loglevel debug

I have no experience with the flv encoder, but if the general VBV rules 
apply to it, it makes no sense to do both of these things at the same time:

1. enable VBV rate control

2. set maxrate == minrate

You are giving conflicting instructions to the encoder.

Have you tried removing -minrate parameter from the command line?

Mike Scheutzow

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